A $1.45 billion agreement between Commerzbank AG and the U.S. government to settle charges that the German bank had violated U.S. sanctions on doing business with Iran and Sudan was approved by a federal judge on April 3.  The federal government agreed to defer prosecution for three years in exchange for penalties paid to the Manhattan District Attorney's office, the Federal Reserve, and the Treasury Department.  If Commerzbank abides by the terms of the agreement, after three years prosecutors will ask that the charges be dropped.  The bank conceded the allegations, which included the processing of more than $250 million in transactions for Iranian and Sudanese entities.